In March’s blog, we discussed what cancer is. We said,
“When a cell is told to multiply, it begins a multi-step process which has “checkpoints.” These checkpoints inspect the cell, ensure it is progressing normally & allow it to continue its development. If a cell is found defective (i.e. several genes have changed or mutated), it will usually self-destruct or it will be removed by other cells (thanks to our immune system). This process is programmed so there is a balance between the cells that multiply & those that die. In cancer, however, this process is defective. Instead of self-destructing or being removed, the defective cell passes through the checkpoints & multiplies at-will.”
This describes one reason people get cancer: Cells malfunction (usually as a result of age or genetic predisposition). However, environmental factors may also contribute. For example, chemicals found in pesticides or in cigarettes (or other forms of tobacco use). UV radiation from too much sun exposure or sunburns has been linked to cancer development. Behavioral factors may also increase risk. For example, an unhealthy diet & sedentary lifestyle can lead to obesity* which increases the risk of developing cancer. Smoking, heavy/regular alcohol consumption, chronic stress & hormones (such as menopausal therapy or oral contraceptives) do as well.
*Obesity & other conditions that cause chronic inflammation (such as chronic inflammatory bowel diseases – e.g. Crohn’s Disease – or even untreated lymphedema) has been linked to cancer. The longer chronic inflammation persists, the greater the risk of cancer development.
References
http://www.cancer.gov/about-cancer/understanding/what-is-cancer
http://www.cancer.gov/about-cancer/causes-prevention
https://www.mdanderson.org/publications/focused-on-health/december-2014/how-stress-affects-cancer-risk.html.html
